syzbot

==================================================================
BUG: KMSAN: uninit-value in __arch_swab32 arch/x86/include/uapi/asm/swab.h:10 [inline]
BUG: KMSAN: uninit-value in __fswab32 include/uapi/linux/swab.h:59 [inline]
BUG: KMSAN: uninit-value in __swab32p include/uapi/linux/swab.h:179 [inline]
BUG: KMSAN: uninit-value in __be32_to_cpup include/uapi/linux/byteorder/little_endian.h:82 [inline]
BUG: KMSAN: uninit-value in get_unaligned_be32 include/linux/unaligned/access_ok.h:30 [inline]
BUG: KMSAN: uninit-value in LOAD_OP crypto/sha256_generic.c:63 [inline]
BUG: KMSAN: uninit-value in sha256_transform crypto/sha256_generic.c:79 [inline]
BUG: KMSAN: uninit-value in sha256_generic_block_fn+0xb05f/0xb460 crypto/sha256_generic.c:238
CPU: 0 PID: 3581 Comm: syzkaller797887 Not tainted 4.16.0+ #83
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
Call Trace:
 __dump_stack lib/dump_stack.c:17 [inline]
 dump_stack+0x185/0x1d0 lib/dump_stack.c:53
 kmsan_report+0x142/0x240 mm/kmsan/kmsan.c:1067
 __msan_warning_32+0x6c/0xb0 mm/kmsan/kmsan_instr.c:676
 __arch_swab32 arch/x86/include/uapi/asm/swab.h:10 [inline]
 __fswab32 include/uapi/linux/swab.h:59 [inline]
 __swab32p include/uapi/linux/swab.h:179 [inline]
 __be32_to_cpup include/uapi/linux/byteorder/little_endian.h:82 [inline]
 get_unaligned_be32 include/linux/unaligned/access_ok.h:30 [inline]
 LOAD_OP crypto/sha256_generic.c:63 [inline]
 sha256_transform crypto/sha256_generic.c:79 [inline]
 sha256_generic_block_fn+0xb05f/0xb460 crypto/sha256_generic.c:238
 sha256_base_do_finalize include/crypto/sha256_base.h:111 [inline]
 sha256_final crypto/sha256_generic.c:252 [inline]
 crypto_sha256_finup+0x35e/0x7e0 crypto/sha256_generic.c:260
 crypto_shash_finup crypto/shash.c:173 [inline]
 shash_ahash_finup+0x468/0xa30 crypto/shash.c:266
 shash_ahash_digest+0x5c6/0x600 crypto/shash.c:306
 shash_async_digest+0x11c/0x1b0 crypto/shash.c:320
 crypto_ahash_op+0x89a/0xc10 crypto/ahash.c:361
 crypto_ahash_digest+0xe4/0x160 crypto/ahash.c:383
 hash_sendpage+0xb40/0xe10 crypto/algif_hash.c:164
 kernel_sendpage net/socket.c:3234 [inline]
 sock_sendpage+0x1de/0x2c0 net/socket.c:855
 pipe_to_sendpage+0x31b/0x430 fs/splice.c:451
 splice_from_pipe_feed fs/splice.c:502 [inline]
 __splice_from_pipe+0x49a/0xf30 fs/splice.c:626
 splice_from_pipe fs/splice.c:661 [inline]
 generic_splice_sendpage+0x1c6/0x2a0 fs/splice.c:832
 do_splice_from fs/splice.c:851 [inline]
 direct_splice_actor+0x19b/0x200 fs/splice.c:1018
 splice_direct_to_actor+0x764/0x1040 fs/splice.c:973
 do_splice_direct+0x335/0x540 fs/splice.c:1061
 do_sendfile+0x1067/0x1e40 fs/read_write.c:1413
 SYSC_sendfile64+0x1b3/0x300 fs/read_write.c:1468
 SyS_sendfile64+0x64/0x90 fs/read_write.c:1460
 do_syscall_64+0x309/0x430 arch/x86/entry/common.c:287
 entry_SYSCALL_64_after_hwframe+0x3d/0xa2
RIP: 0033:0x440c19
RSP: 002b:00000000007dff78 EFLAGS: 00000217 ORIG_RAX: 0000000000000028
RAX: ffffffffffffffda RBX: 00007ffd8f2f7820 RCX: 0000000000440c19
RDX: 0000000020e64ff8 RSI: 0000000000000005 RDI: 0000000000000004
RBP: 0000000000000000 R08: 0000000120080522 R09: 0000000120080522
R10: 0000000000000008 R11: 0000000000000217 R12: 00000000004023b0
R13: 0000000000402440 R14: 0000000000000000 R15: 0000000000000000

Uninit was stored to memory at:
 kmsan_save_stack_with_flags mm/kmsan/kmsan.c:278 [inline]
 kmsan_save_stack mm/kmsan/kmsan.c:293 [inline]
 kmsan_internal_chain_origin+0x12b/0x210 mm/kmsan/kmsan.c:684
 kmsan_memcpy_origins+0x11d/0x170 mm/kmsan/kmsan.c:526
 __msan_memcpy+0x19f/0x1f0 mm/kmsan/kmsan_instr.c:470
 sha256_base_do_update include/crypto/sha256_base.h:88 [inline]
 crypto_sha256_finup+0x1d2/0x7e0 crypto/sha256_generic.c:259
 crypto_shash_finup crypto/shash.c:173 [inline]
 shash_ahash_finup+0x468/0xa30 crypto/shash.c:266
 shash_ahash_digest+0x5c6/0x600 crypto/shash.c:306
 shash_async_digest+0x11c/0x1b0 crypto/shash.c:320
 crypto_ahash_op+0x89a/0xc10 crypto/ahash.c:361
 crypto_ahash_digest+0xe4/0x160 crypto/ahash.c:383
 hash_sendpage+0xb40/0xe10 crypto/algif_hash.c:164
 kernel_sendpage net/socket.c:3234 [inline]
 sock_sendpage+0x1de/0x2c0 net/socket.c:855
 pipe_to_sendpage+0x31b/0x430 fs/splice.c:451
 splice_from_pipe_feed fs/splice.c:502 [inline]
 __splice_from_pipe+0x49a/0xf30 fs/splice.c:626
 splice_from_pipe fs/splice.c:661 [inline]
 generic_splice_sendpage+0x1c6/0x2a0 fs/splice.c:832
 do_splice_from fs/splice.c:851 [inline]
 direct_splice_actor+0x19b/0x200 fs/splice.c:1018
 splice_direct_to_actor+0x764/0x1040 fs/splice.c:973
 do_splice_direct+0x335/0x540 fs/splice.c:1061
 do_sendfile+0x1067/0x1e40 fs/read_write.c:1413
 SYSC_sendfile64+0x1b3/0x300 fs/read_write.c:1468
 SyS_sendfile64+0x64/0x90 fs/read_write.c:1460
 do_syscall_64+0x309/0x430 arch/x86/entry/common.c:287
 entry_SYSCALL_64_after_hwframe+0x3d/0xa2
Uninit was created at:
 kmsan_save_stack_with_flags mm/kmsan/kmsan.c:278 [inline]
 kmsan_alloc_meta_for_pages+0x161/0x3a0 mm/kmsan/kmsan.c:814
 kmsan_alloc_page+0x82/0xe0 mm/kmsan/kmsan.c:868
 __alloc_pages_nodemask+0xf5b/0x5dc0 mm/page_alloc.c:4283
 alloc_pages_vma+0xcc8/0x1800 mm/mempolicy.c:2019
 shmem_alloc_page mm/shmem.c:1471 [inline]
 shmem_alloc_and_acct_page+0x6d5/0x1000 mm/shmem.c:1496
 shmem_getpage_gfp+0x35db/0x5770 mm/shmem.c:1771
 shmem_getpage mm/shmem.c:131 [inline]
 shmem_fallocate+0xde2/0x1610 mm/shmem.c:2939
 vfs_fallocate+0x9dc/0xde0 fs/open.c:319
 SYSC_fallocate+0x119/0x1d0 fs/open.c:342
 SyS_fallocate+0x64/0x90 fs/open.c:336
 do_syscall_64+0x309/0x430 arch/x86/entry/common.c:287
 entry_SYSCALL_64_after_hwframe+0x3d/0xa2
==================================================================